Ebony & Ivory

Ebony & Ivory are Dante's trademark pair of personally customized, semi-automatic pistols, designed to rapidly fire bullets instilled with his demonic power  , and are the only weapon to appear in every installment in the series. The right-handed white gun, Ivory, was custom built for rapid firing and fast draw times, while the left-handed black gun, Ebony, has been modified for long-distance targeting and comfort. In Devil May Cry 3, upgrading it raises its max firepower.

Design
Ebony & Ivory are both -style handguns chambered for the .45 ACP round, and boast a plethora of customized features:
 * Both pistols have been modified with pivot-style triggers as opposed to the 1900's usual straight-pull trigger
 * Both feature custom sight systems; Ebony uses a set of target sights, while Ivory uses a pair of combat sights
 * Both feature ported muzzle compensators that reduce recoil and counteract muzzle flip. Both barrels are extend through the compensators and are ported to match the cuts in the compensators.
 * Both use custom slides that have been noticeably thickened and reinforced along the slide travel rails and around the chamber and firing mechanism. The result is a slide that bears a resemblance to SIG-Sauer's M1900 line.
 * Rails have been bolted to the forward portion of both frames. These rails are used to hold the compensators in place.
 * Both use double-stack magazines with slam-pads.
 * Both have gold-plated magazine releases, hammers, safety switches and triggers.
 * Ebony features a hooked, two-handed trigger-guard, while Ivory uses a more traditional rounded trigger-guard.
 * Both weapons use ergonomic wood grips which are inlaid with portraits of Victorian women; as befits their names, Ebony's is dark-haired, and Ivory's is fair-haired.
 * Ebony's Ejection port is located on the left side of the weapon, as opposed to the right side (as Ebony is meant to be used left-handed, this causes spent brass to be ejected away from Dante.)

In addition, several customized features are inconsistent between the various games:
 * In the original Devil May Cry game, Ebony utilizes an extended safety latch and a spur hammer. Ivory uses a standard length safety latch and a ring hammer. In later incarnations, both feature spur hammers and standard length safety latches.
 * For Devil May Cry 3, Ivory's frame and slide are both completely left-handed, with all of the controls being mirrored from their normal positions.

The inward-facing side of each weapon's slide (Ebony's right and Ivory's left) is engraved with "Ebony & Ivory" in a cursive script along with the unique design of piano keys, further alluding to its name. The outward facing sides (Ebony's left and Ivory's right) are engraved with a dedication to Dante which is explained in Devil May Cry Volume 1 to be from Nell Goldstein:
 * For Tony Redgrave
 * By .45 Art Warks

Oddly enough, this engraving also appears on the Luce & Ombra, a similar set of pistols belonging to Dante's father and used by Trish which the Ebony & Ivory are modeled after.

The model used for the Ivory within Devil May Cry 3: Dante's Awakening gameplay is simply a recolored copy of that used for the Ebony. The spent shells still behave as though the ejection port is pointed outward, appearing out of thin air above the gun and falling to Dante's right side. Dante tends to cross the guns when firing them.

Viewtiful Joe
Dante uses the Ebony & Ivory for his long-ranged attacks.

Sengoku Basara
Nouhime/Lady Butterfly's sixth weapon is Ebony & Ivory.

Bayonetta
Bayonetta briefly uses the Ebony and Ivory as her handguns against a horde of Angels, with Luce & Ombra as the set on her heels, before she obtains her personal set, "Scarborough Fair."

Marvel vs. Capcom 3: Fate of Two Worlds
Dante can use Ebony/Ivory as his crouching light attack (depending on the side he is facing), and can also perform Charged Shots/Twosome Time, Wild Stomp, also called Cold Shower, and Rain Storm, as well as fire them during his ground throws. His new Weasel Shot special, in which Dante leaps backward while firing, and his Million Dollars Hyper Combo, in which Dante fires a volley of bullets, then fires two charged shots in the style he used to finish off Mundus in DMC1 while saying "Jackpot", are newly introduced moves outside the original series.

Background
The Ebony and Ivory are named after the composed by Paul McCartney and Stevie Wonder, which references the black and white construction of  while also referencing racial harmony.

Trivia

 * The Ebony is the only gun that Vergil is ever shown using, during the battle against Arkham in Devil May Cry 3, after stating that he'll "try it [Dante's] way for once."
 * In Devil May Cry 4, in the secret ending, Dante is seen reading a magazine called the "Two HandGun". An image of the guns and a line "Ebony & Ivory™" can be seen on the page Dante is reading.
 * In DmC: Devil May Cry, Dante once again wields, but refers to them as "girls", in contrast to how the original Dante called his pair "guys".
 * In Devil May Cry 3: Dante's Awakening, it is possible to see upon close examination that the "Ebony & Ivory" inscription is on the outward pointing side of Ivory's slide, and also printed in reverse, despite the piano keys still being printed in front, as though the inscription and the piano keys design are two separate designs applied to the weapon.
 * It's possible to see that while there are many inaccuracies to the design of Ebony & Ivory, there respective iron sights are still correct in Devil May Cry 3, as the square texture atop the slide is longer for Ebony (ranged sights) and are shorter for Ivory (accuracy sights).